Rotary engine.



No. 646,393. Patented Mar. 27, [900.

B. SMITH ROTARY ENGINE.

(Application filed June 6, 1898. Ronwed Sept. 11, 1899.) I (No Model.) 3Sheets-Sheet l.

Irl/Uentm'.

1311 ch arcZ S'mt/z.

THE mums PETERS o, m-guuma. wAsumn'rou, 04 c.

No. 646,393. Patented Mar. 27, I900. B. SMITH.

ROTARY ENGINE.

(App lication filed June 6, 1898. Rammed Sept. 11, 1899.)

(No Model.)

3 Sheets-Shbet 2,

Wzinesses x3. 4. p222. we a lbw/Z53,

No. 646,393. Patented Mar. 27, 1900.

. B. SMITH.

ROTARY ENGINE.

Application fllmi June 6, 1898. Renewed Sept. 11, 1899.)

(No Model.) 3 Sheets8heei 3.

N g 2 m H fig Q a B. in

. T E a 5% n a N co & it a m as g N 7 I. A 4

a k W i I a oz Wa"/Tasses.

% Jhvenlvr Z W Jaw/mm! 8mm Nrrno STATES PATENT Fries,

RICHARD SMITH, OF SHERBROOIIE, CANADA ASSIGNOR OF ONE-HALF TO WILLIAMFARWELL, OF SAME PLACE.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent N 0. 646,398, dated March27, 1900. Application filed June 6, 1898. Renewed September 11, 1899-Serial No. 730,183- (No model.)

To aZZ whom, it may concern:

Be it known that I, RICHARD SMITH, of Sherbrooke, in the county ofSherbrooke and Dominiori of Canada, have invented a new and usefulRotary Steam-Engine, of which the fol- .lowing is a specification.

In this engine I obtain, in common with others of its class, theadvantages due to a continuous rotary motion in one direction,

which obviates the waste of steam-power and other loss due to the suddenreversal of motion of the piston of a reciprocating engine, and I haveendeavored in my present engine to reduce to the lowest point possiblethe loss I 5 by friction, especially between the piston and cylinder, towhich rotary engines have heretofore been subject, and at the same timeto secure the greatest amount of power practicable from a given quantityof fuel. I

My invention consists chiefly in certain improvements in the packingdevices, the steam valve-operating mechanism, and the means forregulating the expansion of the steam, as well as in the generalconstruction and details of my machine, all substantially as hereinaftermore particularly set forth and claimed.

The drawings accompanying this specification and illustrating myinvention represent, in Figure 1, an elevation, and in Fig. 2 a ver- 0tical section, of a rotary steam-engine containing my improvedconstruction. Fig. 3is a horizontal section of one of the steam chestsand valves and the sliding or shifting gate and its operative mechanismenlarged. Fig.

5 lis a plan, developed upon aplane, of the camgroove for operating theshifting cylinderhead or gate with such gate shown in section. Fig. 5 isa plan, Fig. 6 a vertical cross-section, and Fig. 7 a horizontalsection, of my 0 engine, the latter figure being on an enlarged scale.Fig. 8 is a diagram of the cut-off mechanism.

In the drawings, 1 represents the general body or case of the engine,which consists of 5 twin vertical circular casings 2 2, terminating atbottom in semifianges or bases 3 3, which together constitute thebed-plate, each casing having upon its interior face and near itscircumference a semicylindrical annularchannel 4 or 4, which when thetwo casings are bolted together face to face form the common pistonchamber or cylinder 5 of the engine.

' The pistons which travel the cylinder 5 are shown, as in the presentinstance, three in number, at (3 6 6, such pistons being cylindrical incross-section and of a diameter to closely fill the cylinder, and thesepistons are to be packed with some one of the various packing devicesnow employed in reciprocating engines for preventing escape of steambetween the piston and cylinder. The pistons 6 are equidistant and aresecured to the periphery of a circular plate or carrier 7, securedaxially to a horizontal shaft 8, mounted at its front end in a bearing 9in the body of the engine and extending rearward through bearings in asuitable standard 10, erected upon the general bed-plate of the engineor .floorof the engine-room in rear of the engine proper. v I

As the periphery of the piston-carrier 7 extends to the pistonchamber orcylinder, it becomes necessary to pack the outer part of such carrier toprevent escape of steam between the piston-chamber' and the inclosurewhich receives the piston-carrier, and to this end I interpose asuitable packing, which in the present instance is shown as composed oftwo circular fiat rings 10 10 contained within oppositely-disposedannular channels in the said casings, these packing-rings being crowdedup to the contiguous face of the piston-carrier by springs 11 11, &c.,which are contained in pockets formed in bosses in the oppositesemicasin gs and exert their stress between the bottom of each pocketand the ring.

Between the body of the engine and the standard 10 and secured axiallyto and rotating with the shaft 8 and in unison with the piston-carrier 7is a circular head or drum 11, in the periphery of which is sunk anendless cam-groove 13. This groove 13 is to operate the shifting gate orcylinder-head and is formed in two alternating divisions or sections 1414 and 15 15, the former being disposed upon one side of the peripheryof the drum and being of considerably-greaterlength than the latter,which are disposed upon the opposite side of such periphery, thedistance between the two sections laterally of the periphery determiningthe extent of throw of the gate. When the antifriction-roll er of therod of the shifting gate is in a long division of the cam-groove, thegate is closed and steam is entering the cylinder to drive a piston.When such roller stands in a short (1i? vision of the groove, the gateis open to permit of passage past it of the next approach ing piston,and the cam-groove is so timed with respect to the mechanism thatoperates the steam-inlet valve that simultaneously with the closing ofthe gate the valve opens to admit steam to the cylinder. If the steam isto work expansively in the cylinder until its pressure therein isreduced to that of the atmosphere, or practically so, or if it is to be'carried under a full head until the piston completes its stroke, ineither case as it is about to exhaust the gate opens.

The gate is not intended to govern the exhaust; but should it, as mightsometimes occur, open before the exhaust proper opens a portion of theexhaust-steam would escape rearward past the gate and exhaust throughthe port next in rear.

The shifting gates or cylinder-heads are shown in the drawings at 1601-16 as disposed upon diametrically-opposite sides of the engine-casingand in alinelnent with the steam chests and valves, as shownin Fig. 7 ofthe drawings, and each is in the form of a flat plate of a size and formin cross-section to tightly till the cylinder transversely of thelatter. Each gate when shut constitutes the cylinder-head to receive theimpact of the steam.

When open, the cylinder is unobstructed and permits of passage of apiston past the gate. Each gate 16 or 16 is contained within a closedbox 17 or 17, secured to the rear of the casing or body of the engineand directly opposite the steam-chests 21 21, each box opening directlyinto the cylinder of the engine, as shown in Fig. 3 of the drawings.Each gate is formed or provided with a stem or rod 18 which extendsoutwardly through an external stuffing-box 19 and a suitablebearing-bracket, such rod carrying at its outer extremity anantifriction roller or stud 21 which takes into the cam-groove 13,before explained.

The steam-valves of the engine are shown at 18 18 as of any well-knownmodern construction, being in the present instance composed of twocircular disks secu red to a com mon stem and operating withoppositely-disposed seats 20, opening into the interior of eachsteam-chest 21 or 21, the steam-supply opening of which is shown at 22.

To operate the valve, I have in the present instance adopted thefollowing mechanism: To the inner end of each piston-rod 23 or 23 ispivoted the outer end of a horizontal link 24: or 24', the opposite orouter end of such link being pivoted to one end of a vertical arm 25 or25, one of such armsviz., 25- being disposed above the axis of theengine and the opposite arm 25 below such axis. The opposite end of eacharm 25 or25 is pivoted to the inner end of a horizontal bar 26 or 26,the outer end of each bar being pivoted to the body of the engine, asshown at 27, the upper lever 26 terminating at its outer and free end ina handle 27 for purposes hereinafter explained. To the outer end of theshaft 8 is fixed a hub 28, upon theperiphcry of which are formed threewiper-cams of equal sweep 29 29 29 these cams being so disposed as towipe in succession against the inner end of each link 24 or 24, and inso doing open each valve alternately to admit steam to the steam-chestsand the cylinder. As each cam successively passes by after opening thevalve such valve is closed by the action of a spring 30, such springinthe pres 'ent instance being a spiral one located in a cell 31, formedin a cap or cover 32, which covers the outer end of the valve-stem, suchspring exerting its stress between the cap and the end of the stem.

The arrangement of the wiper-cams and of the twin-valve-operatingmechanism is such that when one cam is in a position to open the valveto admit steam to the cylinder, as shown by the cam 29 in Fig. 1 of theaccompanying drawings, its fellow cams are out of contact with theopposite valve mechanism and this latter valve is closed. As the cam 20leaves the valve 18 and the latter closes by the action of its springthe cam 29 in advance of it opens the opposite valve 18 to admit steamto the cylinder, the cams thereafter acting to successively open andclose the valves, as will be readily apparent to good mechanics.

To govern the extent of expansion of the steam in the cylinder bycutting olf the supply of such steam at any desired point in thetraverse of a piston, I employ in the present instance a flat annularcircular plate or ring 33, which is applied to the front of theengine-casing in a manner to permit of part ro tation in its bearings,and to the front face of this ring I pivot the lever or bar 26 at apoint approximately near its inner end, as shown at 34. It will be seenthat by turning the ring 33 slightly (by means of the lever 26) in oneor the other direction the upright arms 25 25' are rocked incorresponding manner and the extent of their throw and the movements ofthe valves increased or diminished, as the case may be.

The exhaust-ports of the engine, which are always open to theatmosphere, are two in number, corresponding to the number of valves,and are shown at 28 28 as situated at diametrically-opposite sides ofthe enginecasing and making exit from the cylinder at points slightly inrear of the steam-chests.

The operation of the above-described engine is as follows; Supposing asa startingpoint the gate 16 to be closed and a piston 6 slightly infront of it, the valve 18' in steamchest 21 being about to open by theaction of the wiper-cam 29 which travels in the direction of the arrow40, (see Fig. 7 of the drawings,) and the opposite valve 18 closed byits spring, and the cams 29 and 29 being idle, the antifriction-rollerof the rod of the gate 16 resting in the beginning of one of the longsections of the cam-groove13, steam flowing through the port of valve 18passes between the gate 16 next in front of it and the piston-carrier 7begins its rotation in the direction of the arrows in Figs. 1 and 6 ofthe drawings, and the various pistons begin their traverse of thecylinder, and this continues until the piston first named reaches thepoint at which steam is to be cut off from the cylinder, when thewiper-cam 29 passes by the valve 18 and allows the latter to be closedby the action of its spring, the wiper-cam 29 in the meantime advancingtoward the arm of the opposite valve mechanism in the direction of thearrows before alluded to. The active piston continues its journey untilits stroke of on e-half of the cylinder-is completed, and it passes bythe exhaust-port next in front of it for the escape of theexhaust-steam, the antifriction-roller 21 of the gate 16 during thismovement of the piston remaining in the saidlong section of thecam-groove until the said exhaust-port opens, at which time the rollerof gate 16 enters the short section next ensuing of the cam-groove, andthereby opens the said gate and leaves the cylinder unobstructed topermit of passage of the next advancing piston, which at this time isimmediately behind the gate. As this second piston passes beneath thegate the roller of such gate enters the next or long division of thecam-groove and closes the gate behind the piston. Simultaneously withthis closing of the gate and of the cylinder the Wiper-cam 29 hasreached the arm 25 of the mechanism for operating the opposite valve 18and the latter opens and admits steam between the gate and piston. Thissecond piston now continues its journey until the steam has been cut offand the opposite exhaust-port 42 has been opened and the opposite gateopened to permit of passage of a piston and closed be- .hind it, atwhich time the wiper-cam 29 is about in contact with the arm 25 of themechanism for opening the opposite valve 18' first named, and theantifriction-roller of the gate 16 is in the beginning of the nextensuing long division of the cam groove, (having left the short divisionas the gate closes,) and we are brought to the starting-point.

I claim- 1. The mechanism for operating each valve, consisting of a linkand a valve-stem, to one end of which the said link is connected, incombination with a vertical arm connected to the other end of the saidlink, a lever to which this arm is pivoted, the trip-cams carried by theengine-shaft and acting to open the said valves, the springs which tendto close the latter, and a supporting device on which the said lever ispivoted, substantially as set forth.

2. Themechanismforoperatingeachvalve, consisting of a link and avalve-stem, to one end of which the said link is connected, incombination with a vertical arm connected to the other end of the saidlink, a lever to which this arm is pivoted, the trip-cams carried by theengine-shaft and acting to open the said valves, the springs which tendto close the latter and a ring 33 on which the lovers for operating thevalves are pivoted and the casing on which the said ring is mounted insuch manner as to permit its rotary adjustment, substantially as setforth.

3. In a rotary engine, the combination with a revolving piston-carrierand an engine-case in which it works, of gates 16 and means for movingthem automatically into and out of the cylinder to form partitionstherein or allow the passage of a piston, devices for supplying steambetween such gates and the pistons to continuously drive the carrier,valves for cutting off the supply of steam at any point to regulate itsexpansion, levers for opening the said valves, springs tending to closethe said valves, a series of rotary cams arranged to operate the saidlevers and a series of links connecting the said levers respectively tothe stems of the said valves,

substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

RICHARD SMITH. WVitnesses:

F. CURTIS, O. H. THORNTON.

